Illustrations

Cholesterol is a soft, wax-like substance found in all parts of the body. Your body needs a little bit of cholesterol to work properly. But too much cholesterol can clog your arteries and lead to heart disease.

Some cholesterol is considered "good" and some is considered "bad." Different blood tests are needed to individually measure each type of cholesterol.

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

To get the most accurate results, you should not eat or drink anything for 9 - 12 hours before the test. You may drink water, but avoid other beverages, such as coffee, tea, or soda. For the purpose of screening, the total cholesterol is often done without fasting overnight.

Your health care provider may tell you to stop taking drugs that can affect the test. Never stop taking any medicine without first talking to your doctor.

Total cholesterol is an important measure of both bad and good cholesterol. Other lab tests are done to measure specific amounts of good (HDL) and bad (LDL) cholesterol. A cholesterol breakdown including LDL and HDL is preferred under certain circumstances.

In general, a total cholesterol value over 200 mg/dL may mean you have a greater risk for heart disease. However, LDL levels are a better predictor of heart disease, and they determine how your high cholesterol should be treated.

Any acute illness can raise or lower your total cholesterol number. If you have had an acute illness in the 3 months before having this test, you should have this test repeated in 2 or 3 months. Even a flare-up of arthritis can affect your cholesterol level.

Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Executive summary of the third report of the National Cholesterol Education Program (NCEP) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel III).
JAMA
. 2001;285:2486-2497. Updated 2004.

Review Date: 6/23/2010Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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